Download Practice Problems for Chapter 8

PRACTICE PROBLEMS
CHAPTER EIGHT
CHEM 1311
1. For the following molecules,
(1) SeI2
(2) NO3(3) CO2
(4) PF52How many regions of high electron density (RHED) does each central atom have?
(5) BeClF
2. For each of the molecules in question 1, determine:
(a) the possible bond angles of the molecule.
(b) the hybridization of central atom.
(c) name the electronic geometry of the molecule.
(d) name the molecular geometry of the molecule.
(e) whether the molecule in polar or nonpolar. Explain using a drawing.
3. Sketch the molecules of question 1 showing the correct electronic geometry and molecular geometry of each.
4. How many total sigma and total pi bonds are in the structure of the following molecules?
a) H2O
b) CO2
c) NO3d) PF525. According to the Valence Bond Theory, formation of stable bonds between atoms is the result of __?__ overlap
of atomic or hybrid orbitals.
6. What would be the resultant (a) geometry and (b) bond angles of a set of orbitals resulting from the mixing of
one s atomic orbital, 3 p atomic orbitals and 1 d atomic orbitals? (c) What is the name of the new set of orbitals?
(d) How many individual orbitals would be produced in this new set? (e) When in bonding would this new set of
orbitals be needed by the central atom?
ANSWERS:
1.
(1)
(2)
(3)
(4)
(5)
4 RHED
3 RHED
2 RHED
6 RHED
2 RHED
2.
Molecule
(a)
Bond
angles
(b) Hybridization
of central atom
(c) Electronic
geometry
(d) Molecular
geometry
(e) Polarity
of molecule
SeI2
109.5
sp3
tetrahedral
bent (angular)
polar
NO3-
120
sp2
trigonal planar
trigonal planar
nonpolar
CO2
180
sp
linear
linear
nonpolar
PF52-
180 ;
90
sp3d2
octahedral
square pyramidal
polar
sp
linear
linear
polar
BeClF
180
3. electronic
geometry
molecular geometry
4.
a) 2 sigma, 0 pi
b) 2 sigma, 2 pi
c) 3 sigma, 1 pi
d) 5 sigma, 0 pi
5.
good spatial overlap of orbitals and constructive overlap (like algebraic signs of orbitals)
6.
(a) trigonal bipyramidal
(b) 180 , 120 , and 90
(e) When the central atom has 5 RHED
(c) sp3d
(d) 5